Humans generate and produce waste. The handling of waste is particularly burdensome in military situations, where military units may need to be relatively small and mobile. The personnel in these units will generate waste from both administrative activities and field feeding. This waste generally contains items such as paper, cardboard, plastics and food waste. The personnel also produce waste in the form of black and grey water. The handling and disposal of these waste streams consume significant resources, e.g., labor and energy. Accordingly, there is continued interest in the availability of a mobile, easy to operate, environmentally friendly and efficient system to process waste streams to reduce their volume and mass and to convert the waste into a useful energy source to support the military unit in the field. The advantages of an efficient waste to energy system would greatly simplify the logistics of waste disposal, decrease the consumption of nonrenewable energy required to transport and treat the waste, and supply extra power to meet site-specific needs.
To this end, the Tactical Garbage to Energy Refinery (TGER) was designed and has been iteratively improved responsive to interest and funding from the U.S. Army. The TGER was initially specifically developed as a hybrid system for the tactical disposal of military wastes, accompanied by the generation of usable electrical power. In operation, the 1 ton of waste per day capacity of the TGER was designed to be compatible with support of a force of approximately 550 personnel at remote locations, and the composition of administrative and food waste they generate. Its two main subsystems include gasification and fermentation (bio-reaction), are, separately, established technologies with applications in the treatment of various waste materials.
The TGER system was intended to be capable of converting military field wastes into usable electric power via a standard diesel generator. The TGER utilized a hybrid design of gasification to convert dry solid wastes to syngas and fermentation (i.e., bio-reaction) to process wet food wastes to hydrous ethanol. The syngas and ethanol were then blended with air and fed to the generator, gradually displacing regular diesel fuel. An exemplary implementation of the unit operations involved in the two parallel processes (THERMO for gasification and BIO for bio-reaction) of the TGER system are outlined in prior art FIGS. 1a to 1c. 
An exemplary bio-reaction section of FIG. 1a consisted of a feed station, a bio-reactor, a beer well, two filters, a distillation system, an ethanol tank, and a gray water tank. In this section the feed material is mixed with enzymes, yeast, and antibiotic additives in the bio-reactor to assist in the breakdown of carbohydrates via the fermentation process. The liquid material containing alcohol in the bio-reactor is transferred to the beer well, which serves as a surge tank and fermentation finisher. Sludge is also formed in the bio-reactor that must be periodically removed. The sludge may be dried and added to the feed of the gasifier for additional energy recovery. From the beer well, the aqueous ethanol is pumped through a heat exchanger (using exhaust from the genset as the heating source) to a distillation column. The distillation column operates at about 100° C. with a re-circulating liquid bottom stream to increase the recovery yield of fuel ethanol. A chiller-cooled condenser at the top of the column condenses the vapor. A reflux stream is sent back to the distillation column from the condenser to increase the product purity to 85 percent ethanol with 15 percent water. The final product stream is sent to the storage tank at a rate of about 0.6 gallons per hour. The ethanol is then used, along with the syngas from the gasifier, as fuel for the genset (replacing diesel fuel) to generate electrical power at a target of 60 (kilowatts) kW.
With respect to the exemplary gasification process of FIG. 1b, the pyrolytic gasification section consists of a granulator, mixer, gasifier, high hydrocarbon catalytic converter, two heat exchangers, condenser, dual filters, blower, and syngas surge tank. In this section, typical dry feed, such as a mixture of paper, plastics, cardboard, and recycled bio-reactor sludge, is shredded (to a target particle size of ¼ to ½ inch), mixed, and fed to the auger gasifier. The syngas produced in the gasifier is then conditioned through hot gas filtration, tars/oils catalytic cracking, condensing, and low temperature gas filtration before being fed to the genset through the buffer tank system. The gasifier is operated at a gradient temperature of 200° to 900° C. and atmospheric pressure, with a controlled amount of steam.
Finally, the exemplary genset section of FIG. 1c used is commercially available, e.g., Kohler 60REOZJB generator designed for use with #2 diesel fuel. Minimal changes were made to the genset to accommodate different fuels, e.g., JP-8 (diesel jet fuel). The genset is started using diesel. As syngas and ethanol are available from the TGER process, they replace a portion of the diesel and reduce usage from about 4.6 gallons per hour (gal/hr) to a target of 0.5 gal/hr under normal loading conditions. The syngas and the ethanol are mixed and fed into the fuel-air delivery system of the genset, and diesel is used as needed to maintain the desired electrical generation rate when the syngas and ethanol produced cannot meet the desired power requirement.
The prior art TGER system of FIGS. 1a-1c, though operational, is not optimal. There remains a need for improved subsystems and components to reduce size and footprint, while improving or at least maintaining efficiency. More particularly, to provide maximum support to, e.g., Small Unit Combat Outpost (COP) in austere environments, subsystems and components should be improved so as to address numerous issues related to deployment, black water waste, efficient energy consumption, environmental challenges and security.